    <div class="content" id="signal_content">
        <div style="display: grid; grid-template-columns: 1fr 1fr;">
            <div class="section" style="grid-column: 1;">
                <button class="btn" id="new_signal" onclick="UI.signals.open_signal_Form()">New Signal</button>
            </div>
            <div class="section" style="grid-column: 2;">
                <button class="btn" id="new_external_source" onclick="UI.signals.openSignalTypeForm()">+ External Source</button>
            </div>
        </div>
        <hr>

        <!-- External Sources Section (Real-time only) -->
        <div id="external_sources_section" style="display: none; margin-bottom: 15px;">
            <h3>External Sources <span style="font-size: 11px; color: #888;">(Real-time only - no backtesting)</span></h3>
            <div class="external-sources-container" id="external_sources_list"></div>
            <hr>
        </div>

        <h3>Signals</h3>
        <div class="signals-container" id="signal_list"></div>
    </div>

    <style>
        /* Signals container - flex grid for cards */
        .signals-container {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            padding: 10px;
        }

        /* Individual signal card */
        .signal-item {
            position: relative;
            width: 100px;
            height: 100px;
            border-radius: 10px;
            background: linear-gradient(145deg, #f0f0f0, #cacaca);
            box-shadow: 5px 5px 10px #bebebe, -5px -5px 10px #ffffff;
            cursor: pointer;
            transition: all 0.3s ease;
            overflow: visible;
        }

        .signal-item:hover {
            transform: translateY(-3px);
            box-shadow: 8px 8px 15px #bebebe, -8px -8px 15px #ffffff;
        }

        /* State-based border colors */
        .signal-item.signal-true {
            border: 3px solid #28a745;
            animation: pulse-green 2s infinite;
        }

        .signal-item.signal-false {
            border: 3px solid #dc3545;
        }

        @keyframes pulse-green {
            0% { box-shadow: 0 0 0 0 rgba(40, 167, 69, 0.4); }
            70% { box-shadow: 0 0 0 10px rgba(40, 167, 69, 0); }
            100% { box-shadow: 0 0 0 0 rgba(40, 167, 69, 0); }
        }

        /* Signal icon area */
        .signal-icon {
            width: 100%;
            height: 100%;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 10px;
            position: relative;
        }

        /* CSS-based signal icon */
        .signal-icon::before {
            content: '';
            position: absolute;
            top: 10px;
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .signal-icon::after {
            content: '\2248';  /* Approximately equal symbol */
            position: absolute;
            top: 15px;
            font-size: 28px;
            color: white;
            font-weight: bold;
        }

        /* Signal name */
        .signal-name {
            font-size: 11px;
            font-weight: bold;
            text-align: center;
            color: #333;
            margin-top: 50px;
            word-wrap: break-word;
            max-width: 90px;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }

        /* State indicator */
        .signal-state {
            font-size: 10px;
            font-weight: bold;
            padding: 2px 6px;
            border-radius: 3px;
            margin-top: 3px;
        }

        .signal-true .signal-state {
            background: #28a745;
            color: white;
        }

        .signal-false .signal-state {
            background: #dc3545;
            color: white;
        }

        /* Delete button */
        .signal-item .delete-button {
            position: absolute;
            top: -8px;
            right: -8px;
            width: 22px;
            height: 22px;
            border-radius: 50%;
            background: #dc3545;
            color: white;
            border: 2px solid white;
            font-size: 12px;
            cursor: pointer;
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 10;
            transition: transform 0.2s;
        }

        .signal-item:hover .delete-button {
            display: flex;
        }

        .signal-item .delete-button:hover {
            transform: scale(1.2);
        }

        /* Hover details panel */
        .signal-hover {
            position: absolute;
            top: 110px;
            left: 50%;
            transform: translateX(-50%);
            width: 200px;
            padding: 10px;
            background: white;
            border-radius: 8px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
            z-index: 100;
            display: none;
            font-size: 11px;
        }

        .signal-item:hover .signal-hover {
            display: block;
        }

        .signal-hover strong {
            display: block;
            margin-bottom: 8px;
            font-size: 13px;
            color: #333;
            border-bottom: 1px solid #eee;
            padding-bottom: 5px;
        }

        .signal-details {
            display: flex;
            flex-direction: column;
            gap: 4px;
        }

        .signal-details span {
            color: #666;
        }

        .signal-details .state-true {
            color: #28a745;
            font-weight: bold;
        }

        .signal-details .state-false {
            color: #dc3545;
            font-weight: bold;
        }

        .signal-public-badge {
            display: inline-block;
            background: #17a2b8;
            color: white;
            padding: 2px 6px;
            border-radius: 3px;
            font-size: 9px;
            margin-top: 5px;
        }

        /* External Sources Styles */
        .external-sources-container {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            padding: 10px;
        }

        .external-source-item {
            position: relative;
            padding: 10px 15px;
            background: linear-gradient(145deg, #2a2a2a, #1e1e1e);
            border: 1px solid #444;
            border-radius: 8px;
            min-width: 150px;
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .external-source-item:hover {
            border-color: #17a2b8;
            transform: translateY(-2px);
        }

        .external-source-item .source-name {
            font-weight: bold;
            color: #e0e0e0;
            font-size: 13px;
            margin-bottom: 5px;
        }

        .external-source-item .source-value {
            font-size: 20px;
            font-weight: bold;
            color: #17a2b8;
        }

        .external-source-item .source-time {
            font-size: 10px;
            color: #888;
            margin-top: 5px;
        }

        .external-source-item .delete-source-btn {
            position: absolute;
            top: 5px;
            right: 5px;
            width: 18px;
            height: 18px;
            border-radius: 50%;
            background: #dc3545;
            color: white;
            border: none;
            font-size: 10px;
            cursor: pointer;
            display: none;
            align-items: center;
            justify-content: center;
        }

        .external-source-item:hover .delete-source-btn {
            display: flex;
        }

        .external-source-item .refresh-btn {
            position: absolute;
            top: 5px;
            right: 28px;
            width: 18px;
            height: 18px;
            border-radius: 50%;
            background: #28a745;
            color: white;
            border: none;
            font-size: 10px;
            cursor: pointer;
            display: none;
            align-items: center;
            justify-content: center;
        }

        .external-source-item:hover .refresh-btn {
            display: flex;
        }

        /* External Indicators Styles */
        .external-indicators-container {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            padding: 10px;
        }

        .external-indicator-item {
            position: relative;
            padding: 10px 15px;
            background: linear-gradient(145deg, #3d2a5a, #2a1e3e);
            border: 1px solid #6f42c1;
            border-radius: 8px;
            min-width: 150px;
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .external-indicator-item:hover {
            border-color: #9f7aea;
            transform: translateY(-2px);
        }

        .external-indicator-item .indicator-name {
            font-weight: bold;
            color: #e0e0e0;
            font-size: 13px;
            margin-bottom: 5px;
        }

        .external-indicator-item .indicator-type {
            font-size: 11px;
            color: #9f7aea;
        }

        .external-indicator-item .delete-indicator-btn {
            position: absolute;
            top: 5px;
            right: 5px;
            width: 18px;
            height: 18px;
            border-radius: 50%;
            background: #dc3545;
            color: white;
            border: none;
            font-size: 10px;
            cursor: pointer;
            display: none;
            align-items: center;
            justify-content: center;
        }

        .external-indicator-item:hover .delete-indicator-btn {
            display: flex;
        }
    </style>
